Re: [PATCH net-next 1/3] net: phy: mscc: add support for RGMII MAC mode

[Quentin Schulz <foss@0leil.net>]

Hi Antoine,

I guess I slipped through in your Cc list but now that it's too late to 
undo it, I'll give my 2¢ :)

On 2020-02-27 16:28, Antoine Tenart wrote:
> This patch adds support for connecting VSC8584 PHYs to the MAC using
> RGMII.
> 
> Signed-off-by: Antoine Tenart <antoine.tenart@bootlin.com>
> ---
>  drivers/net/phy/mscc.c | 33 +++++++++++++++++++++------------
>  1 file changed, 21 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/net/phy/mscc.c b/drivers/net/phy/mscc.c
> index d24577de0775..ecb45c43e5ed 100644
> --- a/drivers/net/phy/mscc.c
> +++ b/drivers/net/phy/mscc.c
> @@ -272,6 +272,7 @@ enum macsec_bank {
>  #define MAC_CFG_MASK			  0xc000
>  #define MAC_CFG_SGMII			  0x0000
>  #define MAC_CFG_QSGMII			  0x4000
> +#define MAC_CFG_RGMII			  0x8000
> 
>  /* Test page Registers */
>  #define MSCC_PHY_TEST_PAGE_5		  5
> @@ -2751,27 +2752,35 @@ static int vsc8584_config_init(struct
> phy_device *phydev)
> 
>  	val = phy_base_read(phydev, MSCC_PHY_MAC_CFG_FASTLINK);
>  	val &= ~MAC_CFG_MASK;
> -	if (phydev->interface == PHY_INTERFACE_MODE_QSGMII)
> +	if (phydev->interface == PHY_INTERFACE_MODE_QSGMII) {
>  		val |= MAC_CFG_QSGMII;
> -	else
> +	} else if (phydev->interface == PHY_INTERFACE_MODE_SGMII) {
>  		val |= MAC_CFG_SGMII;
> +	} else if (phy_interface_mode_is_rgmii(phydev->interface)) {

Nitpick:
I don't know much the difference between that one and 
phy_interface_is_rgmii wrt when one should be used and not the other, 
but seeing the implementation 
(https://elixir.bootlin.com/linux/latest/source/include/linux/phy.h#L999)... 
we should be safe :) Since you already have a phydev in hands at that 
time, maybe using phy_interface_is_rgmii would be cleaner? (shorter).

> +		val |= MAC_CFG_RGMII;
> +	} else {
> +		ret = -EINVAL;
> +		goto err;
> +	}
> 
>  	ret = phy_base_write(phydev, MSCC_PHY_MAC_CFG_FASTLINK, val);
>  	if (ret)
>  		goto err;
> 
> -	val = PROC_CMD_MCB_ACCESS_MAC_CONF | PROC_CMD_RST_CONF_PORT |
> -		PROC_CMD_READ_MOD_WRITE_PORT;
> -	if (phydev->interface == PHY_INTERFACE_MODE_QSGMII)
> -		val |= PROC_CMD_QSGMII_MAC;
> -	else
> -		val |= PROC_CMD_SGMII_MAC;
> +	if (!phy_interface_mode_is_rgmii(phydev->interface)) {

Ditto.

Thanks,
Quentin